multiple #use RS232 settings on one usart

[kusterh]

Hi,

I've got a problem using multiple settings on the same (built in) usart.
In my application the usart is connected to a modem, and this modem runs in two modes:
- 19k2 baud, 8n1
- 9600 baud, 8e1
So in my program I have to switch between these two modes depending on the state of the modem and I can't figure out how to do this.
I've tried the following:
#use RS232 (...., STREAM=x)
#use RS232 (...., STREAM=y)
fprintf(x,...);
fprintf(y,...);
Here x and y should correspond to the same usart, with different settings, but this doesn't work, all output is done with the last #use setting.
Also tried:
#use RS232 (....)
void putcx(char)
#use RS232 (....)
void putcy(char)
printf(putcx,...);
printf(putcy,...);
This also doesn't work, again only the last #use setting is used.
At last I also tried this:
(in the main code before each printf line)
#use RS232 (....)
printf(....);
You guessed right, this also doesn't work, all data is output with the same settings. :-(

Does anyone know how this can be done ?
Thanks,

Herman
___________________________
This message was ported from CCS's old forum
Original Post ID: 11149

[Tomi]

As I know there is no "on-the-fly" config setting by #use rs232 for built-in UART. The hardware is initiated at startup as your last #use line says.
The speed part of your problem is simple: just use "Set_UART_Speed(baudrate)"

The parity part could be more complicated.
Maybe the best solution is to set up the UART for 9-bit data and write your own parity calc./check function with an input bit to indicate your needs. (If no parity is necessary then it is equivalent with a 2-stop-bits transmission and an ignored parity receive.)

:=Hi,
:=
:=I've got a problem using multiple settings on the same (built in) usart.
:=In my application the usart is connected to a modem, and this modem runs in two modes:
:=- 19k2 baud, 8n1
:=- 9600 baud, 8e1
:=So in my program I have to switch between these two modes depending on the state of the modem and I can't figure out how to do this.
:=I've tried the following:
:=#use RS232 (...., STREAM=x)
:=#use RS232 (...., STREAM=y)
:=fprintf(x,...);
:=fprintf(y,...);
:=Here x and y should correspond to the same usart, with different settings, but this doesn't work, all output is done with the last #use setting.
:=Also tried:
:=#use RS232 (....)
:=void putcx(char)
:=#use RS232 (....)
:=void putcy(char)
:=printf(putcx,...);
:=printf(putcy,...);
:=This also doesn't work, again only the last #use setting is used.
:=At last I also tried this:
:=(in the main code before each printf line)
:=#use RS232 (....)
:=printf(....);
:=You guessed right, this also doesn't work, all data is output with the same settings. :-(
:=
:=Does anyone know how this can be done ?
:=Thanks,
:=
:=Herman
___________________________
This message was ported from CCS's old forum
Original Post ID: 11152

[kusterh]

<font face="Courier New" size=-1>I was wondering some more: I don't have to use the usart (the amount of data i have to send to the modem is fairly low), so if i used a bitbanged rs232 interface (i.e. #use RS232 with some general io pins as tx and rx) would the compiler switch correctly between even and no parity ?
I just looked into the generated .lst file and it looks like the generated assembly code indeed is different now for the two settings. For now I can't test it any further because this involves hardware modifications and these are not possible.

:=As I know there is no "on-the-fly" config setting by #use rs232 for built-in UART. The hardware is initiated at startup as your last #use line says.
:=The speed part of your problem is simple: just use "Set_UART_Speed(baudrate)"
:=
:=The parity part could be more complicated.
:=Maybe the best solution is to set up the UART for 9-bit data and write your own parity calc./check function with an input bit to indicate your needs. (If no parity is necessary then it is equivalent with a 2-stop-bits transmission and an ignored parity receive.)
:=
:=:=Hi,
:=:=
:=:=I've got a problem using multiple settings on the same (built in) usart.
:=:=In my application the usart is connected to a modem, and this modem runs in two modes:
:=:=- 19k2 baud, 8n1
:=:=- 9600 baud, 8e1
:=:=So in my program I have to switch between these two modes depending on the state of the modem and I can't figure out how to do this.
:=:=I've tried the following:
:=:=#use RS232 (...., STREAM=x)
:=:=#use RS232 (...., STREAM=y)
:=:=fprintf(x,...);
:=:=fprintf(y,...);
:=:=Here x and y should correspond to the same usart, with different settings, but this doesn't work, all output is done with the last #use setting.
:=:=Also tried:
:=:=#use RS232 (....)
:=:=void putcx(char)
:=:=#use RS232 (....)
:=:=void putcy(char)
:=:=printf(putcx,...);
:=:=printf(putcy,...);
:=:=This also doesn't work, again only the last #use setting is used.
:=:=At last I also tried this:
:=:=(in the main code before each printf line)
:=:=#use RS232 (....)
:=:=printf(....);
:=:=You guessed right, this also doesn't work, all data is output with the same settings. :-(
:=:=
:=:=Does anyone know how this can be done ?
:=:=Thanks,
:=:=
:=:=Herman</font>
___________________________
This message was ported from CCS's old forum
Original Post ID: 11157

[Tomi]

The answer is theoretically "yes" (but IMHO you have to check the code and have to choose a version what really does it )

:=so if i used a bitbanged rs232 interface (i.e. #use RS232 with some general io pins as tx and rx) would the compiler switch correctly between even and no parity ?
___________________________
This message was ported from CCS's old forum
Original Post ID: 11162